PROCSIMA proposes using diffractionless beamed propulsion to enable interstellar travel at very high speed. My presentation focused on PROCSIMA's NIAC Phase I report by Christopher Limbach and Ken Hara from 2019 – today, the research continues.
PROCSIMA uses the model mission of travelling to Proxima Centauri, with the novel propulsion shortening the travel time to only 42 years, assuming 0,1c velocity with 1 kilogram payload. Their idea relies on the Photon-paRticle Optically Coupled Solion Interstellar Mission Accelerator, which increases probe acceleration distance by a factor of ca 10,000. If successful, this technology could be used for a plethora of missions – including studying Oort cloud objects or the solar gravitational lens (from 500AU).
The key innovation concept behind PROCSIMA is combining neutral particle beam and laser beam so that no spread nor diffraction occurs on propagation. They propose tailoring the mutual interaction of laser and particle beams, so that the refractive index variations produced by the particle beam generate a waveguide effect, eliminating the laser diffraction. The particle beam, in turn, is trapped in the regions of high electric field strength near the centre of the laser beam. This results in a soliton. Simply put, the laser and particle beam transmitter shoots out the laser and particles which push the probe forward.
The key challenges lie in said transmitter – the key parameters being brightness and mass flow rate. Current technology does not yet allow for breakthrough there, but the authors are convinced that we will get there soon enough. One important aspect is the synergies created across research for improving all kinds of future beam systems.
The concept was found credible according to mathematics and literature research; Limbach and Hara also identified the need to further investigate ion-neutral and cold collision cross sections for the technology. Their study showed that at 0.1c, the payload capability was only 5 grams. Reducing to 0.44-0.75c would enable 1-60kg, which would be a lot more feasible.
Source:
Limbach, C., & Hara, K. (2019). PROCSIMA: Diffractionless Beamed Propulsion for Breakthrough Interstellar Missions.